First, psychologists don't do medication, psychiatrists do. Second, you're too young for medication and this problem isn't one for medication, it's one to solve. Doctors won't help you with this -- the psychologist is the expert on this, not your doctor -- doctors don't study psychology. Clearly, you have an insecurity problem, which is so common at your age. Have you talked about this with your friends, or are your relationships confined to the internet? Real people face to face are much more, well, real than the internet, and they tend to be more understanding. You've very young -- you're just starting out on something new and you're more nervous about it than most but all of us were nervous at first and most of stay nervous all our lives when it comes to meeting people we are sexually interested in. Some people do it easily, but most of don't ever do it easily. We just do it. Usually, it works out okay as it goes along until it doesn't, but that's another story. I think you're taking this too seriously, expecting yourself to be more than humans really are. Get off the internet and interact more with real people. It will take time, but you probably needed some time to learn everything you've learned -- this is no different. Keep working with the psychologist, but try to work on why you feel so insecure over something everyone goes through, why you're making yourself so miserable over this at such a young age? I don't know if you play a sport, but if you do I bet you got a lot better over time than you were at the beginning. Sex is just like that. Learn to ease up on yourself and I think you'll see you're just a normal 16 year old.
First, psychologists don't do medication, psychiatrists do. Second, you're too young for medication and this problem isn't one for medication, it's one to solve. Doctors won't help you with this -- the psychologist is the expert on this, not your doctor -- doctors don't study psychology. Clearly, you have an insecurity problem, which is so common at your age. Have you talked about this with your friends, or are your relationships confined to the internet? Real people face to face are much more, well, real than the internet, and they tend to be more understanding. You've very young -- you're just starting out on something new and you're more nervous about it than most but all of us were nervous at first and most of stay nervous all our lives when it comes to meeting people we are sexually interested in. Some people do it easily, but most of don't ever do it easily. We just do it. Usually, it works out okay as it goes along until it doesn't, but that's another story. I think you're taking this too seriously, expecting yourself to be more than humans really are. Get off the internet and interact more with real people. It will take time, but you probably needed some time to learn everything you've learned -- this is no different. Keep working with the psychologist, but try to work on why you feel so insecure over something everyone goes through, why you're making yourself so miserable over this at such a young age? I don't know if you play a sport, but if you do I bet you got a lot better over time than you were at the beginning. Sex is just like that. Learn to ease up on yourself and I think you'll see you're just a normal 16 year old.
Have you gone to the doctor? I have anxiety as well, and I used to feel very sick when I would get anxious. I started on anxiety medication when I started college because it was a big change for me. I still get anxious now, but it is much better than it used to be. I would recommend going to a doctor to talk about it. If you are against taking anxiety medications or if you want to try something else first, then I would try journaling or yoga. Journaling was especially helpful for me because I felt that a weight had been lifted off of my shoulders. I've heard that yoga can be very therapeutic.
The nausea is from fear so that is your only problem. Is there a counselor at your school who you can talk this over with?